使用优先队列实现Huffman树

Posted 2020-10-03 上后谈爱情

 1 package com.mmall.common.Test;
 2 
 3 import java.util.Comparator;
 4 import java.util.PriorityQueue;
 5 import java.util.Queue;
 6 
 7 /**
 8  * Created by Workstation on 2017/8/9.
 9  */
10 public class HuffmanCode {
11 
12    private class HuffNode implements Comparable<HuffNode>
13     {
14         HuffNode Left;
15         HuffNode Right;
16         int val;
17 
18         public HuffNode (HuffNode left, HuffNode right, int val) {
19             Left = left;
20             Right = right;
21             this.val = val;
22         }
23 
24         @Override
25         public int compareTo (HuffNode o) {
26             return this.val-o.val;
27         }
28     }
29 
30 
31 
32 
33     public void CreateHuffmanTree(int [] weight)
34     {
35         //创建一个优先的队列;其中的值按照最小堆方式创建
36         PriorityQueue<HuffNode> priorityQueue=new PriorityQueue<HuffNode> ();
37 
38 
39         for(int i=0;i<weight.length;i++)
40         {
41             HuffNode node=new HuffNode (null,null,weight[i]);
42             priorityQueue.add(node);
43         }
44 
45         HuffNode node1=null;// 最小权值点
46         HuffNode node2=null;// 次最小权值点
47         HuffNode node3=null;//合并的值
48 
49         for(int j=0;j<weight.length-1;j++)
50         {
51             node1=priorityQueue.poll ();
52             node2=priorityQueue.poll ();
53             node3=new HuffNode (node1,node2,node1.val+node2.val);
54             priorityQueue.offer(node3);
55         }
56 
57         System.out.println(priorityQueue.peek ().val);
58     }
59 }